I have recently been fiddling around with making a simple UI (in order to make a word bubble/panel thingy like console rpgs that shows up along the bottom).? Instead of using g2d to draw it, I decided to make the UI in 3D (like EVE Online does, for instance).? So I set up a quad and applied a simple png texture that is basically a black gradient that fades to transparentness.

The problem is, there's this thin, light-grey line that shows up on the edge of the quad, where there is only transparent pixels in the texture (see where the yellow arrow is pointing to).

There is a quad that is really close to the camera at the bottom of the view.? Its texture is a semi-transparent black gradient that fades out at the top of the quad.? The quad ends where that grey line is (i.e. the grey line is showing up on the edge of the quad).

On further experimentation, I noticed that it only appears when the quad is certain sizes... so I don't really know what could be causing it.? I'm changing the way the quad will be rendered (in orthogonal projection mode versus in the actual 3d scene) so I'm hoping it will go away then.